Control mechanism for power punch presses



Mag; 6', 1924. r 1,493,272

H. PAECHT CONTROL MECHANISM FOR POWER PUNCH PRESSES Filed March 23. 1921 2 Sheets-Sheet 1 May 6, 1924.

H. PAECHT CONTROL MECHANISM FOR POWER PUNCH PRESSES Filed March 23 1921 2 Sheets-Sheet 2 Patented May 6, 19 2 4.

UNITED STATES PATENT oFF cs.

HUGO PAECHT, OF NEW HAVEN, CONNECTICUT, ASSIGNOR TOTHE STANDARD SAFETY MFG. 00., OF NEW HAVEN, CONNECTICUT, A CORPORATION.

CONTROL MECHANISM FOR POWER PUNCH PRESSES.

Application filed March 23, 1921. I Serial No. 454,811.

To all whom it may concern:

Be it known that I, HUGO PAEoHT, a citizen of the United States, residing at New Haven, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Control Mechanism for'Power Punch Presses; and I do hereby declare the following, when taken in connection with the accompanying drawings and the characters of reference, marked thereon, to be a full, clear, andexact description of the same, and which said drawings constitute part of this application, and represent, in

Fig. 1 a side view of a foot-release powerv punch press, equipped with my improved non-repeating mechanism, shown in a normal, or at rest, position.

Fig. 2 a similar view showing the treadle depressed, and the plunger at, or substantially at, the limit of its downward movement, and the ped'al-lifting-cam in position about to function.

Fig. 3 a broken detail view of the treadle releasig mechanism, shown in the released position.

Fig. 4 a broken sectional view of the outer end of the driving-shaft with parts connected therewith.

This invention relates to improvement in control mechanism for power punch presses. In the more general construction of power punch presses, if the pedal is held depressed the punch will continue to move up and down as long as the pedal is held depressed,

and it frequently occurs that if the operator is not quick in removing his work, after the completion of the punching operation, that the punch will descend again and damage the dies or the stock previously operated upon.

The object of this invention is to provide means for disconnecting the pedal after each operation, or after each downward movement of the punch, provided the operator fails to allow the pedal to rise, so as to re quire a positive and separate movement of the pedal for each operation.

In illustrating my invention I have shown the usual form of power drop press, including a frame 10, a plunger 11, an anvil 12, and in connection with a safety device like that shown and described in an application filed in even date herewith, which includes a pedal 13, pitman 14, which operates the guard through mechanism described in the said application but which is not essential to this invention other than that the pitman 14 isconnected at its upper end with a coupling-head 16, formed with a guide stem 17 reciprocating in a socket 18, in the lower end of a latch carrier 19, which is pivotally connected to an arm 20 which oscillates a shaft to move the guard 15 of the safety guard operating mechanism, such as shown in Patent No. 1,086,059. The arm 20 is. provided with a roller 41 on a pin 42 which rides in a cam-slot 43 in a plate 44 pivoted toa stud 47 on 'afbracket secured to the frame of the machine, and having a downwardly-projecting arm 46 withwhich the rod 33 is pivoted. The arm 46 and the plate 44 are both hung on the same stud 47, and are yieldingly coupled together by a spring 48 to avoid breakage of the parts, in case of a jam. The latch carrier is provided with a lug or extension 21 to which is pivoted a latch 22, the nose 23 of which will engage with the coupling head 16 under pressure of a latch spring 38. The upper end 24 of the latch is outwardly offset, and coupled by a link 25 to one arm 26 of a bell-crank lever, the other arm 27 of whichextends upward and is provided with a clearance-notch 28, the arm 27 standing in the path of a cam 29 on a collar 30 fixed to a driven shaft 31. The

purpose of the notch is to clear the cam 29 when the same passes the end of the arm 27. In other words, the notch permits the end of the arm to drop off from the rear end of the cam.

A downward movement of the treadle 13 presses the arm 26 into the ath of the cam 29 and, at the same time, t e usual releasing-dog 32 is moved by the rod 33 to start the downward movement of the plunger 11, this being done by moving the releasing dog 32 out of engagement with the spring-key 34, which snaps into a notch 35 in the driving-wheel 36, thereby coupling that wheel with the shaft 31. As the shaft 31 com pletes its revolution, the cam 29 engages with the bell-crank lever, and rocks the latch 22 into the position shown in Fig. 3, and so as to disengage the nose 23 from the head 16, allowing the carrier 19 and the parts connected therewith to be drawn up by the bell-crank-lever 2627 Without pulling the treadle with them, thereby pushing the dog 32 against the shaft, which will withdraw the key 34 and uncouple the driving-wheel 36 from the shaft 31, and the movement of the plunger is thereby stopped, and this oconrs during each revolution. It will be understood that the wheel 36 is constantly driven. In order to start the ma.- chine again, the operator must lift his foot to release the pedal, which, under the action of a pedal spring 37, will rise and cause the head 16 to be reengaged by the nose 23 of the latch 22, and the pedal is thereby again coupled up so as to be in position to again start the press. Attention is called to the fact that the latch 22 is positively disengaged from the head 16 by the action of the cam 29 striking the arm 27 of the bellcrank-lever. Preferably, and as shown, the guard 15 will be provided with a screen 39 to prevent the operator from inserting his hand over the top of this guard.

I claim:

1. In a power press, the combination with a driven shaft, a driving wheel, a clutch key for coupling the said wheel with said shaft, a plunger operated by said shaft, of a cam on said driven shaft, a lever, which extends into the path of the said team, a foot-pedal provided with a head, a latch carrier, a latch on said carrier adapted to engage with said head, a connection between said latch and said lever, and means operated by the pedal for positively moving the said key.

2. In a power press, the combination with a driven shaft, a driving wheel, a clutch key for coupling the said wheel with said shaft, a plunger operated by said shaft, of a cam on said driven shaft, a lever, which extends into the path of the said cam, a footpedal provided with ,a head, a latch carrier, a latch on said carrier adapted to engage with said head, a connection between said latch and said lever, and a cam operated by the pedal for positively moving the said rey.

In testimony whereof, I have signed this specification in the presence of two sub scribing witnesses.

HUGO PAEGHT.

Witnesses Frnonn o ,G. EARLE, MALCOLM P. NIoHo s. 

